Because of the introduction of new integer encoding types for ziplists in the 2.6 tree, the same integer value may have a different encoding in different versions of the ziplist implementation. This means that the encoding can NOT be used as a fast path in comparing integers.
…nce. The new implementation start reading / writing before blocking with aeWait(), likely the descriptor can accept writes or has buffered data inside and we can go faster, otherwise we get an error and wait. This change has effects on speed but also on correctness: on socket errors when we perform non blocking connect(2) write is performed ASAP and the error is returned ASAP before waiting. So the practical effect is that now a Redis slave is more available if it can not connect to the master, previously the slave continued to block on syncWrite() trying to send SYNC, and serving commands very slowly.
…t to no. We used to reply -ERR ... message ..., now the reply is instead -MASTERDOWN ... message ... so that it can be distinguished easily by the other error conditions.
…ow more reliable.
Every matched key in a KEYS call is checked for expiration. When the key is set to expire, the call to `getExpire` will assert that the key also exists in the main dictionary. This in turn causes a rehashing step to be executed. Rehashing a dictionary when there is an iterator active may result in the iterator emitting duplicate entries, or not emitting some entries at all. By using a safe iterator, the rehash step is omitted.
An user reported a crash with Redis scripting (see issue #480 on github), inspection of the kindly provided strack trace showed that server.lua_caller was probably set to NULL. The stack trace also slowed that the call to the hook was originating from a point where we just used to set/get a few global variables in the Lua state. What was happening is that we did not set the timeout hook selectively only when the user script was called. Now we set it more selectively, specifically only in the context of the lua_pcall() call, and make sure to remove the hook when the call returns. Otherwise the hook can get called in random contexts every time we do something with the Lua state.
A previous commit removed -g -rdynamic -ggdb as LDFLAGS, not allowing Redis to produce a stack trace wth symbol names on crash. This commit fixes the issue.
This commit reverts most of c575766, in order to use back main stack for signal handling. The main reason is that otherwise it is completely pointless that we do a lot of efforts to print the stack trace on crash, and the content of the stack and registers as well. Using an alternate stack broken this feature completely.
Now it uses the new wait_for_condition testing primitive. Also wait_for_condition implementation was fixed in this commit to properly escape the expr command and its argument.
A new primitive wait_for_condition was introduced in the scripting engine that makes waiting for events simpler, so that it is simpler to write tests that are more resistant to timing issues.
1) One integer "immediate" encoding that can encode from 0 to 12 in the encoding byte itself. 2) One 8 bit signed integer encoding that can encode 8 bit signed small integers in a single byte. The idea is to exploit all the not used bits we have around in a backward compatible way.